The invention relates to a truck-mounted concrete pump having a vehicle and a concrete spreading boom that is arranged on said vehicle, said concrete spreading boom comprising multiple boom arms that can be stowed as an arm assembly on a boom resting unit that is fixed to the vehicle, and a boom hydraulics system that is embodied so as to stow and to unfold the arm assembly, said boom hydraulics system comprising a first hydraulic cylinder that moves the arm assembly in a stowing movement against the boom resting unit.
In the case of such mobile concrete pumps, the distributor boom that guides the concrete supply line is folded for transporting and is stowed on a section that is spaced apart from the rotating joint for the first boom arm on the boom resting unit or a boom pedestal so that transverse movements in the driving state or boom movements when driving on for example uneven roads are avoided as much as possible. It is possible when using the hydraulic system to press the arm assembly so intensely downwards that even in the case of travelling on roads an improved fixing arrangement is achieved by means of bracing the arm assembly against the substructure; however, in the event of operator error an undesired plastic deformation of the substructure or damage to the chassis occurs.